Over the weekend, a rumour spread like wildfire through Apple and Mac circles which stated that starting with Mac OS X 10.7, Apple would introduce the App Store model to the Mac, allowing only Apple-approved applications to run. It became apparent to me right away that this was a load of nonsense, and for once, I was right: Steve Jobs has personally dismissed the rumour.

While I've no doubt that His Steveness would love to control the Mac the way he controls the iPhone OS, he's not stupid. To do so would all but guarantee the death of the Macintosh user base and, from there, the product line. They were only able to do it with the iPhone OS because it was a new product and there were no expectations surrounding it regarding third party apps.
That being said, I would not oppose a package manager for OS X or at least a way to reliably remove apps. If you've ever tried to remove an app completely on OS X you know what hell it can be. OS X has the easiest method of installing apps (at least of the oses without a package management system) but there's no functionality whatsoever for removing the files the app puts all over the darn place. It's actually worse than Windows, at least *some* apps in Windows come with uninstallers that actually work.